Existing telecommunications networks, such as the public switched telephone network (PSTN) are typically configured so that equipment (such as switches) in the transmission or bearer network, which carries user traffic (voice and data signals), is co-located with equipment (such as signaling points) in the associated signaling network, which carries control signals for coordinating the operation of the bearer network.
However, telecommunications networks are migrating to a distributed architecture in which the equipment that carries user traffic is separated from the equipment that provides signaling functionality Furthermore, a modern communication network typically comprises dissimilar networks that are coupled together. Such dissimilar networks can include, for example, the PSTN coupled to a packet network. These dissimilar networks generally employ different bearer technologies and/or signaling protocols.
Dissimilar telecommunications networks are typically interconnected via a “gateway” which provides the necessary conversions or adaptations between the bearer traffic and signaling protocol in each of the networks. In such an architecture an adaptation device, such as a media gateway (MG) (sometimes referred to as a “trunk gateway”) can be used to couple the dissimilar networks. A control device, such as a media gateway controller (MGC), provides control functionality over the media gateway, but need not be co-located with the media gateway. Generally, the media gateway passes voice and data information. A media gateway controller can communicate with one or more media gateways using a control protocol, such as, for example, simple gateway control protocol (SGCP) and media gateway control protocol (MGCP).
Typically, a media gateway and a media gateway controller are each coupled to both a PSTN and a packet network. The media gateway controller may communicate with other media gateway controllers over the PSTN using extensions of current call control protocols such as Signaling System No.7 ISDN User Part (SS7 ISUP), Session Initiation Protocol (SIP—IETF RFC 2543), ITU Recommendation H.323, or Transaction Capabilities Application Part (TCAP). New protocols may be defined for this interface in the future.
A media gateway controller communicates with a media gateway using, for example, MGCP. Accordingly, the media gateway does receive signaling messages, but they are received from the media gateway controller.
When user traffic, such as a telephone call occurring between a node located in the PSTN and a node located in the packet network, spans the dissimilar communication networks, the user traffic is identified differently by the two communication networks.
Protocol monitoring applications, such as tracing across a signaling network the protocol messages associated with a call, or building a call data record (CDR) to summarize the key parameters relating to user traffic (i.e., a telephone call) requires the ability to map call identifiers across different protocols, which may refer to a single entity in multiple different, inconsistent ways.
Therefore, it would be desirable to have a network analysis device that is capable of mapping two or more different communication protocols referring to the same user traffic in a communication network that comprises at least two dissimilar communication networks.